Final answer:
The normal rating of a lead acid storage battery is 12 V, which is due to six cells in series, each rated at 2 V. Lead acid batteries are used in automobiles for their high current output and low cost.
Step-by-step explanation:
The normal rating for a lead acid storage battery is 12 V. This is because each cell within the battery has an open circuit voltage of approximately 2.2 V, but in practice, they are normally rated at 2 V per cell. Therefore, a typical car battery, which consists of six cells in series, would have a total voltage of 12 V (6 cells x 2 V per cell). Regardless of their individual open circuit voltages, the cells are designed to work together to provide the necessary power to start a car or power other electrical systems.
The lead-acid battery's popularity as a power source in automobiles and marine engines is largely due to its ability to provide high current output at a relatively low cost. The cells in a lead-acid battery are made up of plates or grids of lead and powdered lead dioxide, immersed in an electrolyte of sulfuric acid, which allows for repeated discharging and recharging of the battery.